Electrical connector



I Jan. 9, 1940.

J. G. DEBBY ELECTRICAL CONNECTOR Filed April 25, 1956 INVENTOR. JOHN EDmay.

ATTORNEY.

Patented Jan. 9, 1940 John G. Debby, Cleveland, Ohio Application April23, 1936, SerialNo. 76,061

Claims.

This invention relates to electrical connectors and particularly toelectrical switches for carrying heavy currents.

One of the principal objects of the present invention is to provide aconnector of this character in which better and higher pressure contactbetween the blade and blade receiving clips is effected so that theswitch is capable of carry- U ing greater currents without danger ofburning and overheating and with a reduction in current losses throughthe connections.

A more specific object is to provide a switch in which positive wedgingcontact pressure is effected merely by throwing the switch in the usualmanner and in whichthe switch is maintained in the closed conditionwithout loosening under vibrational and other such forces by suchwedging pressure.

Another object of the present invention is to effect adequate contactpressure between the the blades and the blade supports.

Another objectis to provide a switch of this character in which theusual limit stops are eliminated. l

Other objects and advantages will become apparent from the followingspecification wherein reference is made to the drawing in which Fig. lisa plan view of a switch embodying the principles of the presentinvention, the switch being shown in open condition;

Fig. 2 is a plan view 0 the switch in closed condition; i

Figs. 3 and 4 are vertical sectional views, taken on planes indicated bythe lines 3-3 and 4-4 respectively in Fig. 2;

Fig. 5 is a vertical sectional view taken on a plane indicated by theline 5-5 in Fig. 3;

Fig.- 6 is a perspective view of a contact and clamping element used inconnection with the present invention; and I Fig. '7 is a sectional viewsimilar to Fig. 4 illustrating a modification of the invention.

For the purposes of illustration, the invention is shown in connectionwith the usual blade type switch, its use in connection with other typesof connectors being readily apparent therefrom.

Heretofore in switches of this character, means havebeen provided forlimiting the separation of the blade receiving clip arms so as toprovide a better contact between the arms and the blade. In other types,this contact has been increased by the use of screw wedges which, afterthe switch is thrown, are screwed into place so as to wedge the bladeand clips tightly together. Even in this latter type, however, thewedging actionis such that the contact pressure is dependent upon therigidity of the clip arms.

regardless of the rigidity of the blade or clip and, inv additionthereto, the path for the current is doubled. I

In the present structure, adequate wedging pressure is obtained 7Referring to the drawing, the switch, designated generally as l,comprises the usual insulating base 2 at one end of which are carriedthe blade receiving clips 3 and at the other end of which are mountedthe movablecontact blades 4, the latter being secured together by asuitable insulating bridge 5, carrying the usual operating handle, 6. Asbetter illustrated in Figs. 3 and 4, each of the clips 3 comprises apair of spaced arms 1 which are preferably formed integral with eachother and are secured to the base 2 by suitable means such as the screws8.

The arms I, at their blade receiving portion, are spaced apart adistance equal to the thickness of the blade 4 to be associatedtherewith and have plane adjacent contact surfaces. These surfaces mayconverge slightly toward the base 2, so as to guide the bladetherebetween but they are so related that when the blade is therebetweenand the arms are wedged into operating positionagainst the blade, thesurfaces are parallel with the cooperating surfaces of the bladepermanently fixed directly on the arms I. The

portions la may be cast out of brass or copper plated steel integralwith the arms I or the usual copper strip arms may be used with thewedge portions 1a soldered thereto so as to form therewith asubstantially unitary structure. "In either event the portions 1a are ofconducting'material and connected to the arms with a highly efiicientelectrical connection.

Carried one on each blade 4 are rigid frames Ill, each frame comprisingrigid side frame members Illa and rigid end frame members lb. The sideframe members extend generally parallel to theassociated blade and arespaced apart from each other and .fromopposite faces of the blade sothat the wedge portions Ta of the arms 1 may be received, one wedgeportion between each side frame member Mia and the blade 4 when theblade is moved to position between the arms. The end frame members arepreferably spaced apart a distance slightly greater longitudinally ofthe blade than the corresponding dimension of the clip arms I so as tocompensate for the arcuate path of the blades l as they enter the cliparms.

The illustrative embodiment is one in which the frames IE are providedfor installation on a standard switch blade, the provision of such in aspecialized switch being readily apparent. In the illustrativeembodiment, the frames iii are sep arately formed and mounted on thearms t. For this purpose, the end frame members lllb are provided withslots lllc through which the blade 4 is received. If desired, the frameit may be mounted with slight clearance edgewise of the bladelongitudinally thereof so that it may adjust itself conveniently orreadily for slight inaccuracies in manufacture. For rough manufactureslight transverse clearance may be allowed also. The inner surfaces ofthe frame members Eda are convergent toward the free ends of the cliparms l and parallel respectively to the Wedge portions lla' of the arms,thus providing wedge portions led which are in fixedly spaced relationto each other transversely of the blade. Thus when the blade d is swungdownwardly between the clip arms 1, the wedge portions la of the armsand illd of the frame cooperate to wedge the arms into firm face to facecontact with the opposite faces of the blade i, the pressure exertedbeing extremely great so that a highly efficient contact pressurebetween the blades and arms is obtained.

Here it should be noted that when attempts are made in switches to Wedgethe blade laterally outwardly against oneof the clip arms, or to wedgeone arm tightly against the blade, spreading of the arms apart, due totheir own resiliency, or a movement and deflection of both the blade andthe arms away from the wedge result so that only part of the force ofthe wedge is effective unless the blade or arms, or both, are extremelyrigid or heavily buttressed. In the present structure, however, equaland opposite forces are applied by the wedges at opposite faces of theblade so that equilibrium is obtained and the arms and blade aresubjected only to direct compressive stresses. Since the forces of thewedges are in opposition to each other, extraneous buttressing of thearms or blade against the force of the wedges is unnecessary. The wedgesare so related that the blade is fully between the arms before anyappreciable wedging pressure is exerted, so as to insure full finalsurface contact with the blade. Obviously, the wedging pressure,however, is partially applied at the initial operation of the wedges asa result of which wiping contact under appreciable pressure between theblade and the complementary contact surfaces of the arms i is ob tained.Due to the coaction of the wedge por tions and the clamping of the bladetherebetween, limiting of movement of the blade 1 towards the base 2beyond a predetermined position is effected by the same wedge portions,this limit being reached after the arms have been pressed firmly againstthe blade. Consequently no bottom or end limit abutment such as iscustomary in switch clips is necessary. In fact, such is undesirable asit might be reached by the blade after long use and Wear before the andits associated connector.

wedges are in full clamping position. With the present structure andwithout the limit stop, however, a great amount of wear is possiblebefore the switch is inefficient as the wedge portions inherentlycompensate for the wear and insure stopping of the blade between thearms. Having thus obtained such effective contact between the blade andarms, equally effective contact is inherently provided between the Wedgeportions la and wedge portions lfld of the frame members Ella.

In order to utilize this greater contact area for carrying current whileat the same time eliminating losses in its passage from the framemembers to the blades through the comparatively loose connectionafforded, flexible shunts ll of adequate capacity are permanentlysoldered or connected to the side frame members Holland, in turn,connected permanently to the blades 4. The shunts ii are preferably ofwoven wire and of such capacity that they themselves can carry half ormore of the current passing through the switch. Thus when the switch isclosed, four distinct large surface area contacts and paths for thecurrent are provided between each blade Again, the shunts it serve tosecure the frames in position longitudinally on the blades 1 whilepermitting slight limited movement thereof along the blades, so

that the frames can accommodate themselves readily to the clips.

The arms i tend normally to spring apart slightly when the pressure isremoved and will be in engagement with the side frame members We or theblade l until the wedging pressure is completely removed, at which timea quick separation over the entire surface of one or the other iseffected and, since both the blade and frames are conductors, sparkingand burning are eliminated.

The blades 3 are mounted in the customary manner between the arms ofsuitable supports l2, being pivotally secured thereto by bolts I 3 whichdraw the arms tightly into contact with the butt ends of the associatedblades. Since, however, the larger current carrying capacity for a givensize switch is provided by the frames ii] and shunts H and due to themore efficient contact between the switch blade and the clip arms i, itquite often happens that the current carrying capacity at thisconnection is greater or more efficient than between the arms of thesupports l2 and blades i, especially if for any reason the bolts 13become loosened.

In order to provide better contact between the butt of each blade andthe supports l2, each blade may be provided with a spring yoke M, suchas illustrated in Fig. 6, of highly conductive and spring material. Eachof the yokes it comprises arm portions Mia adapted to receivetherebetween the switch blade i and clamping portions Mb. The yokes Mare mounted permanently on the blades t near the butt ends thereof andadjacent the supports 82, suitable clampin being effected by means of abolt-I5, as illustrated in Fig. 3. When so mounted, the clampingportions Mb of the wires 14 extend rearwardly in a position to pass overand engage respectively the outer surfaces of the arms of the supports52 when the blades 4 are moved to closed position. The portions lib arepreferably flared slightly apart toward the support 12 so as to beguided into place thereon. When the switchis closed, the yokes M pressthe arms of the supports 12 firmly against the faces of 2. An electricswitch having a blade with subthe associated blades. 4 and at the sametime provide a firm but yieldable electrical contact between theportions Mb and the arms of the support 12. Thus, again, four distinctcurrent paths and contact surfaces are provided at the butt end of eachblade and wiping action is obtained at all contacts.

In some instances it is desirable to utilize this invention inconnection with a double throw switch. For such purposes the structureillustrated in Fig. 7 may be utilized. In this modified structure, theparts corresponding to the parts heretofore described are indicated bycorresponding primed numerals. The primary difference between this andthe previous structure resides in the wedges utilized which will bedescribed specifically.

extensive with the arms in the direction of movement of the blade 4.Instead, they merge with oppositely facing wedge portions 2011- whichcooperate with the opposite set of fuse clip arms customarily providedin a double throw switch. In operation, however, the advantages are thesame in either instance. Obviously, in a double throw switch, if yokemembers, such as the mem- I bers M, were provided, double sets ofclamping portions Mb would be necessary so as to engage the bladesupports of the double throw switch regardless in which operatingposition the blade 47 might be disposed' Since the current carryingcapacity of a switch is largely determined by the surface area of theconductors and by the efficiency of the contact surfaces and the contactpressure, it is apparent that the present structure is capable ofcarrying a great amount of current for a given size of switch incomparison with structures heretofore provided. Obviously, in thoseinstances Where laminated blades are used, the frames It may be.

formed by bending outwardly the end portions of the outer laminations,thus forming, in effect, a frame structure, but in such instance, it isusually desirable to reinforce the same due to the yieldability of thecopper and the tendency .of the same to stretch and spread and thuspartially relieve the wedging action. In those instances in which theblade receiving clip comprises only a single arm, equally effectivecontact between'such arm and a single face of the blade can be obtained.

Having thus described'my invention, I claim: 1. An electrical connectorhaving a blade and. a clip the latter having arm portions adapted toreceive the blade between them in sliding engagement therewith, meansmounting the blade and clip for relative movement enabling separationand bringing together of said parts substantially in the samerelationship each time the connector is operated, a frame member on theblade with mutually rigid opposite side portions, positioned forengagement with respective arms, the engaging surfaces of the framesides and arms being 7 angularly disposed so that they wedge againsteach other to increase the pressure between the slidably engagedsurfaces and finally arrest the sliding relative movement of the bladeand arms.

stantially parallel opposite sides and a clip with spaced surfaces whichface each other and are substantially parallel when engaged with saidvblade surfaces, spaced mutually rigid members on the blade and similarlyspaced non-yielding surfaces on the arms, said members and surfacesbeing angularly related in a mann'erto effect -mutual wedging to causethe first-named clip surfaces to press against the parallel blade sideswhen the blade and clip are moved relatively into circuit-closingposition.

3.- In an electric switch, a blade of current carrying material, a clipof current-carrying material havingarms adapted and arranged to embraceand make contact with the blade, a substantially rigid metallic framecarried on the blade with sufficient lcoseness to permit floatingmovement of the frame on the blade,said frame having spaced relativelyfixed surfaces adapted to make Wedging, travel-limiting contact withouter side surfaces of the arms for increasing the contact pressurebetween the blade and arms and forming a stop against furtherm'ovementwhen the switch is closed, and flexible, electrically conductive meansconnecting the frame and blade.

' l. In an electrical switchdevice, a connector having a pair of spacedcontact arms, a blade ,mounted for movement from an open to a closedposition and received between the arms when in: closed position, wedgemeans on the outer faces of saidvarms, cooperating Wedge members carriedby the blade and engageable with said wedge Imeans for moving the armsrelatively'toward each other and against the blade when the blade isreceived between the arms, means rigidly constraining saidwedge'surfaces from relative separation transversely of the blade overtheir entire operating faces, and means mounting said wedge members onthe blade for slight floating movement longitudinally of the blade.

a 5. In an electrical connector including a contact member having apair, of spaced contact arms with free end portions, a movable blademember mounted for movement edgewise into position between said armsfrom'the free end portions thereof, a transversely rigid framecarriedfby the blade member and having end frame portions and side frameportions which are connected at their ends to the end frame portions andwhich are spaced laterally from the blade member, said frame being openat the edge, of the blade member, internal wedge members carried by saidside frame-members and spaced out-' wardly fromopposite faces of theblade member, respectively, for accommodating the arms between the wedgemembers and the blade when the blade is moved into contact position withthe arms, said internal wedge membersbeing divergent in the direction ofmovement of the blade toward contact position, complementary wedgemembers on the outer faces of the arms and cooperable with the internalwedge members, re-.

spectively, for moving the arms into firm con tacting engagement withthe blade when the 7 blade is moved tocontact position to materiallyincrease the contact pressure between the arms and blade and to limitthe movement of the blade edgewise between the arms when the blade ismoved into position between the arms;

JOHN G. DEBBY.

